Cancer and treatment related symptoms rarely occur in isolation and cause patients distress, thus treatment of symptoms must begin to address the co-occurrence of multiple symptoms. Symptom clustering in cancer patients is a new field of inquiry and to date little is known about the symptom cluster experience of elderly cancer patients. This study is a secondary data analysis of 972 persons aged 65 years or older and newly diagnosed with breast, colorectal, lung or prostate cancer. The purposes of this study are to determine: 1) the prevalence of the co-occurrence of pain, fatigue and insomnia; 2) the conditions under which this triad of symptoms co-occur; 3) which symptoms cluster together; 4) the stability of these symptom clusters at 6,12, 24, and 52 weeks following the incident cancer diagnosis; and 5) how symptom clustering may differ based upon site of cancer or stage of disease (early versus late). The knowledge gained from this study will help to illuminate the symptom cluster experiences of elderly cancer patients through the first year following an incident diagnosis of cancer and provide the foundation for developing symptom management strategies for elderly cancer patients who endure the co-occurrence of multiple symptoms.